REBOA TOOLKIT
– Which equipment should be used in a bleeding patient and how? –
Imagine being on a weekend emergency night shift; while you are sipping your coffee and re-evaluating your patients with their laboratory results, suddenly your phone rings and it’s 112 command and control centre calling. It informs that an in-vehicle traffic accident will be brought within 10 minutes and patient’s condition is bad. Dozens of questions pop into your mind and you find yourself asking questions such as “Is resuscitation room ready?”, “Are surgeons available on this night shift?”, “Is there any available ICU bed at the moment?”, “Is interventional radiologist available?”, “Is there sufficient blood products available in blood bank?”…etc. First of all, take a deep breath and evaluate the situation you are in. Consider the resources at your disposal, inform the units you need to notify in advance and be confident.
The patient came and was taken to the resuscitation room, you started resuscitation using the traditional ABCDE approach. The patient is in stage-3 hemorrhagic shock and there must be something you can do at this point. The A(a)BCDE approach, which is the one of the innovations brought by endovascular trauma management (EVTM) to the traditional ABCDE approach, integrates arterial access -as a lowercase (a)- in addition to our traditional patient management. Long story short, arterial access is the first step of EVTM. And all the equipment we use from this step can be included in the REBOA toolkit.
The artery we frequently use while providing arterial access is common femoral artery (CFA). And the method we use while doing this-which we are all familiar with- is Seldinger Technique. To briefly mention, the materials we use at this stage are our Seldinger needle, which can be 4,7 or 9 cm in length, our guide wire, which can also be of different lengths and thicknesses, and our smooth, silicone sheath that provides the permanence of access, starting from 4-5 French (Fr) thickness, and a flexible dilator that allows the sheath to move easily in the skin, subcutaneous tissue and in the vein. (Picture-1) Of course, since we perform our artery puncture with an Ultrasound (USG), a linear probe and an USG can be included in the REBOA toolkit as well. In addition, it is not easy to provide arterial access in every patient therefore we should also have a cut-down set at the ready.
Picture-1. Arterial Sheath
Arterial sheaths are produced in a wide range starting from 4 Fr to 24 Fr. The most important factor determining our sheath selection is the thickness of the REBOA catheter we have. We must provide access with a sheath of appropriate thickness which the catheter in our disposal can pass through. Unfortunately, we can’t say “Whatever, let’s use 24 Fr sheath, the bigger the better”, because in an average human, the femoral artery diameter is about 5-7 mm. A 7 Fr sheath covers 17% of the femoral artery, while the 12 Fr sheath covers 50%. In other words, as the thickness increases, the rate of development of major complications such as ischemia and necrosis in the ipsilateral leg increases. Since we provide the arterial access during primary care of the trauma patient, it is difficult to predict whether one of the EVTM techniques will be used. For this reason, it would be the most appropriate approach to provide access with a relatively thin sheath at the beginning and then to do the widening which also known as “upsizing”, in accordance with the EVTM technique and material we will use. Even if the patient is not a suitable candidate for EVTM, you will have an arterial access to obtain blood samples, to make intermittent arterial blood gas analyses and even to monitor invasive blood pressure. In a study by Chung et al., 320 patients with a femoral arterial access were evaluated. A 4 Fr sheath was used in 168 of 320 patients and a 6 Fr sheath in 152. There was no significant difference in the development of major complications requiring additional treatment in these 2 groups. Therefore, it seems reasonable to initially provide arterial access with a 4 or 6 Fr sheath.
If arterial access is provided and it is decided that the patient is suitable for REBOA, then we can start to talk about balloon catheters to perform this process. Balloon catheters are flexible catheters that have a balloon at their distal ends that can be inflated with fluid infusion. These are used for many years in medicine to open the blocked arteries or to occlude the target vessel when necessary. Some of them are specially produced for REBOA, while others are used in other indications, and found suitable for REBOA. The first catheters I will mention are Cook Medical's Coda balloon catheter and Medtronic's Reliant balloon catheter. These catheters are wide and long catheters used by cardiovascular surgeons in procedures such as EVAR and TEVAR. So that; while we need to use 12-14 Fr arterial sheath for Coda, Reliant is compatible with 12 Fr sheath. Their length varies between 100-140 cm. Can they be used for REBOA? Yes, they can but the risk of complications will be high (Picture -2). Another catheter available for EVTM is the Edwards Fogarty catheter which are generally used for embolectomy procedure. In many subtypes of Fogarty catheter, balloon diameters are not sufficient for complete occlusion of the aorta, and the adequate balloon sized subtypes are compatible with 22 Fr arterial sheath. In the light of these information, it is difficult to say that Fogarty would be the perfect fit to perform the REBOA. There are balloon catheters produced exclusively for REBOA. The most famous of these are REBOA Medical’s REBOA Balloon Kit, Tokai’s Rescue Balloon, Prytime’s ER-REBOA and Frontline’s COBRA-OS balloon catheter. (Picture-3) The difference of REBOA Balloon Kit from others; it is presented as a complete set including sterile cover, sterile sponges, sterile gloves and even a pincushion as well. Rescue Balloon, on the other hand, stands out with its 40 mm balloon diameter, providing an advantage for total occlusion of the aorta. Alternatively, the ER-REBOA catheter is an assertive catheter with its double lumen and patented P-type structure which is specially placed at the distal end to prevent possible damage to the vascular endothelium. These 3 catheters mentioned above are compatible with 7 Fr sheath and have CE marking. COBRA-OS, a newer catheter, is compatible with a 4 Fr arterial sheath, making it the thinnest REBOA catheter on the market which can provide a total occlusion of the aorta. However, as of today, COBRA-OS hasn’t received CE mark approval yet. At the end of the day, they all have advantages and disadvantages over each other. At this point, the clinician should choose the appropriate catheter according to the patient and his/her own experience.
In this text, i tried to briefly talk about REBOA toolkit. In order to use this toolkit, you must receive training. In addition to self-improvement, collaboration with such branches as interventional radiology, Cardiovascular Surgery, Intensive Care Medicine is mandatory. Although this whole EVTM concept may seem like a gruelling work, the professional satisfaction of saving lives is invaluable.
Picture-2. Coda and Reliant balloon catheter
Picture-3. REBOA Balloon Kit, Rescue Balloon, ER-REBOA, COBRA-OS
References:
- Matsumura Y., Falkenberg M., Delle M., et al. “The bleeding patient and your tool kit. What and how to use?”. Top Stent; The art of endovascular hybrid trauma and bleeding management, edited by Hörer T.M., Örebro University Hospital, c/o KärlThorax kliniken, 2017, 45-63.
- Okada et al. “Lower limb ischemia caused by resuscitative balloon occlusion of aorta”. Surgical Case Reports, 2016;2:130.
- Chung et al. “Are complication rates lower with 4-Fr versus 6-Fr transfemoral arterial access - prospective audit at a single interventional radiology centre”. CVIR Endovascular, 2018;1:15.
- Cook Medical 2022, accessed 08.02.2022, <https://www.cookmedical.com/products/829e48bc-8fa0-43e5-9530-11ded12b6a42/>
- Medtronic 2020, accessed 08.02.2022,
- REBOA Medical 2022, accessed 08.02.2022, < https://reboamedical.com>
- Tokai Medical Products, accessed 08.02.2022, <https://www.tokaimedpro.co.jp/english/products/endovascular/000081.html>
- Prytime Medical, accessed 08.02.2022, < https://prytimemedical.com>
- Frontline Medical Technologies 2022, accessed 08.02.2022,
